The widespread deployment of high-speed networking and communications equipment has produced a large demand for various types of networking communication components and subsystems. Included among these, are packages, which are often referred to as photonic packages.
An important aspect of optical components, such as optical components used in telecommunications and data communications technology (i.e., lightwave communications), is the monitoring of a semiconductor light source within a photonic package. Often times, the semiconductor light source may be in the form of a semiconductor laser. Monitoring of the semiconductor light source, such as the semiconductor laser, is important because light emitted from the semiconductor light source carries data. In order to facilitate monitoring of the semiconductor laser, often times, the semiconductor laser is manufactured in such a way as to emit light in two directions. The two directions that the semiconductor laser may emit light are known as a front facet and a back facet.
Light emitted from the front facet of the semiconductor laser is commonly coupled to an optical fiber for data transmission. Light emitted from the back facet is commonly provided to a photodiode for monitoring. Because light emitted from the back facet is a percentage of the light emitted from the front facet, monitoring the light emitted from the back facet provides information regarding light emitted from the front facet. This monitoring is commonly referred to as back-facet monitoring (BFM). Accordingly, various information regarding light being provided to the optical fiber for transmission may be determined from the photodiode monitoring light emitted from the back facet.
Conventional photonic packages typically include a case, or housing, within which electrical and optical components, such as the semiconductor laser and the photodiode, are enclosed. Such a housing provides physical protection for the components therein, and provides thermal conductivity so that heat may be dissipated from the components disposed within the case. The number of components may be numerous. However, a requirement of the housing is that the housing be of a small form factor. Accordingly, in order to have the components within a housing of a small form factor, placement of the components is an important aspect of the photonic package.
Placement of the components may be determined by one component's operation relative to another's. For example, as described above, a component, such as a semiconductor light source, that operates to provide light-based signals is placed in such a manner as to be optically coupled to another component, such as an optical fiber, that operates to optically transmit light-based signals. Accordingly, placement of the photodetector is opposite the side of the semiconductor light source coupled to the optical fiber.
As the sophistication of the photonic packages increases, the number of components may increase as well. However, the form factor of the housing of the photonic package continues to become smaller. As a result, placement of the photodetector in the light path opposite the optical fiber side of the semiconductor light source becomes increasingly difficult due to various components included in the housing.
Thus, an improved approach for monitoring a semiconductor light source within a photonic package is desired.